Two Catholic moral theologians consider the ethics of taking up arms in self-defence against an overwhelmingly superior military force

The courageous and inspirational Ukrainians are responding to Russia’s invasion of their country with both nonviolent and armed resistance. We watch on our mobile phones with anguish and concern as Ukrainian civilians in the city of Melitopol plant themselves in front of armoured military vehicles with astonishing courage, shouting “Murderers!” and “Occupants!” as Russian soldiers fire gunshots into the air. At the same time, we watch as Russian citizens march through their cities chanting “No More War!”, bravely risking arrest and long prison sentences. Civil resistance is alive in Ukraine. Civil disobedience is alive in Russia.

Nonviolence, as Pope Francis has emphasised, is central for Catholics. Beside its shameful complicity in war and conquest, Christianity can claim a long tradition of nonviolent resistance to injustice, from Jesus turning the tables of the money changers in the Temple marketplace and the refusal of early Christian martyrs like Ss Perpetua and Felicitas to honour Roman imperial gods, to the peace witness of Menno Simons during the Reformation-era religious wars, to modern faith-based activists who have joined with ­others to resist apartheid in South Africa, racism in the US, corruption in the Philippines and tyranny under the communist bloc.